We have studied the electronic states in three different ceria thin film surfaces prepared on a Cu(111) single-crystal surface by vapor deposition at different conditions: at 250 °C, at room temperature and finally Au-doped ceria film obtained by simultaneous deposition of Au and CeO 2 at room temperature (RT). Electronic properties of the layers and interaction of gold with CeO 2 were investigated with use of synchrotron-radiation-excited PES and resonant photoemission (Ce 4d → 4f transitions). We have observed partial Ce 4+ → Ce 3+ reduction induced by decrease of deposition temperature to RT instead 250 °C and also by doping ceria by gold, accompanied by a 4f resonance enhancement of the Ce 3+ species. In the case of Au-doped sample the surface reduction degree is stronger and can be explained by the possible creation of new ionic Au + state peaks observed in the Au 4f spectra.